Computer vision systems are systems that analyze camera generated images and enable useful conclusions to be reached from that analysis. Such systems often comprise digitizing an analog image to produce a table of digital data. Thereafter, a digital computer processes the digital data, for example, to locate edges, recognize shapes, or to verify spatial relationships. Computer vision systems are in their infancy but some truly useful applications already exist. Eyetrackers are a splendid example of computer vision systems. An eyetracker is a device that measures the movements of the eye upon which the camera is trained. Specifically, an eyetracker detects the direction an eye is gazing. An eyetracker communication system allows a physically handicapped person to use eye gaze and movement to communicate. In our copending patent application Ser. No. 551,309 entitled "An Eyetracker Communication System" assigned to the same assignee as this application, a complete eyetracker communication system is disclosed. In that system a very high quality video camera was required to generate the image to be digitized. It had been hoped that the system would enable many seriouly handicapped individuals to lead a better life. Unfortunately, the size of the system and the expense of the components of the system were a serious drawback.
This application discloses and claims an eyetracker communication system that is miniature compared to the earlier system and substantially less expensive. It now appears that the earlier hopes can be realized. The video camera has been eliminated altogether. It has been replaced by a solid state image sensor. The eyetracker has been totally reorganized and revised to use the type and quality of data available from the image sensor. This patent application describes a specific and unique application of a solid state image sensor which is described, for example, in U.S. Pat. No. 4,441,125. Another application of a similar device is described in Byte, The Small Systems Journal, Volume 8, No. 9, pp. 20 et seq. and No. 10, pp. 64 et seq. (September and October 1983). The specific solid state image sensor that is used in the physical embodiment described in this patent application is detailed in the sales literature of Micron Technology, Inc., Bulletin IS256 1A effective 11-1-85.